Clinical features of uveitis HLA B27 in patients with uveitis associated with ankylosing spondylitis and reactive arthritis. The study was made on 64 patients with uveitis treated in the municipal hospital between 2005-2008. The diagnosis was established after a complex ophthalmologic investigation. Histocompatibility HLA-B27 was determined in all groups of patients. Each patient was consulted by the rheumatologist. In the study were included 50 (78%) men and 14 (22%) women. The frequency of HLA B27+ was 72%. At HLA B27+ associated with ankylosing spondylitis and reactive arthritis is present in the anterior form in 85%, unilateral affection in 92%. Their evolution is chronic in 17% and has a tendency for recidivism in 11% of patients. HLA B27 is a genetic factor of uveitis associated with spondylarthropathies in 72%. The study determined the disease in 78% of men, 72% were acute, 85% were anterior and 92% were unilateral. The study of HLA B27 in patients with uveitis is one of the shortest ways for the earlier diagnosis of ankylosing spondylitis.